From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2BF91C4BA0B for ; Wed, 26 Feb 2020 10:25:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9FFD20801 for ; Wed, 26 Feb 2020 10:25:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="kO7xRmXr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727929AbgBZKZr (ORCPT ); Wed, 26 Feb 2020 05:25:47 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:41234 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726057AbgBZKZq (ORCPT ); Wed, 26 Feb 2020 05:25:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=FO1jzBBBEj3/sIx+JDo2aKN1rmyxAa885Lrp4ivQReA=; b=kO7xRmXriSWDiRXcKH+wucKgHo 5QhtiEz8uU8nC+HJ+7T7Zv474HmwmuyFi7OqKTWsFLihQ0LfjXQThkDvwpuxXcI1OBBfLJr1BV2Rg SKLJ19BQoSMGpRDA84qNU7o4qdTukBrtHAyytjbf8YE73J8URjZ3feXMtPurdFTnpCjKI7YwwdCNs 4kZE7GNvS+lFuiiktSGcqYgturG753TMPd/v3DQwrXarbFJa5YuXeL5JoT+n0vscATizbHS7fUqaU CQloQdEswcJsHGAC621Z7+Lj6+sDqS2oOFBLdyOeq3hNPw62vG7Mlwz2KtA9/Z1voXU6h7vtlES7q MQvIuh0w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6tsQ-0006xb-49; Wed, 26 Feb 2020 10:25:14 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 01C0E300130; Wed, 26 Feb 2020 11:23:13 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 56F2020160BF2; Wed, 26 Feb 2020 11:25:09 +0100 (CET) Date: Wed, 26 Feb 2020 11:25:09 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: Andy Lutomirski , LKML , linux-arch , Ingo Molnar , Joel Fernandes , Greg KH , gustavo@embeddedor.com, Thomas Gleixner , paulmck@kernel.org, Josh Triplett , Mathieu Desnoyers , Lai Jiangshan , Tony Luck , Frederic Weisbecker , Dan Carpenter , Masami Hiramatsu Subject: Re: [PATCH v4 05/27] x86: Replace ist_enter() with nmi_enter() Message-ID: <20200226102509.GU18400@hirez.programming.kicks-ass.net> References: <20200221133416.777099322@infradead.org> <20200221134215.328642621@infradead.org> <20200221202246.GA14897@hirez.programming.kicks-ass.net> <20200224104346.GJ14946@hirez.programming.kicks-ass.net> <20200224112708.4f307ba3@gandalf.local.home> <20200224163409.GJ18400@hirez.programming.kicks-ass.net> <20200224114754.0fb798c1@gandalf.local.home> <20200224213139.GO11457@worktop.programming.kicks-ass.net> <20200224170231.3807931d@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200224170231.3807931d@gandalf.local.home> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 24, 2020 at 05:02:31PM -0500, Steven Rostedt wrote: > On Mon, 24 Feb 2020 22:31:39 +0100 > Peter Zijlstra wrote: > > > > Just want to confirm that printk_nmi_enter(), lockdep_off(), > > > and ftrace_nmi_enter() are all marked fully with NOKPROBE. > > > > *sigh*, right you are, I only looked at notrace, not nokprobe. > > > > In particular the ftrace one is a bit off a mess, let me sort through > > that. > > ftrace_nmi_enter() has two purposes. One, for archs that need to deal with > NMIs while they still use stop machine. Although, it appears sh is the only > arch that does that. I can look to see if it can be ripped out. Already done :-) --- Subject: sh/ftrace: Move arch_ftrace_nmi_{enter,exit} into nmi exception From: Peter Zijlstra Date: Mon Feb 24 22:26:21 CET 2020 SuperH is the last remaining user of arch_ftrace_nmi_{enter,exit}(), remove it from the generic code and into the SuperH code. Signed-off-by: Peter Zijlstra (Intel) --- Documentation/trace/ftrace-design.rst | 8 -------- arch/sh/Kconfig | 1 - arch/sh/kernel/traps.c | 12 ++++++++++++ include/linux/ftrace_irq.h | 11 ----------- kernel/trace/Kconfig | 10 ---------- 5 files changed, 12 insertions(+), 30 deletions(-) --- a/Documentation/trace/ftrace-design.rst +++ b/Documentation/trace/ftrace-design.rst @@ -229,14 +229,6 @@ Adding support for it is easy: just defi pass the return address pointer as the 'retp' argument to ftrace_push_return_trace(). -HAVE_FTRACE_NMI_ENTER ---------------------- - -If you can't trace NMI functions, then skip this option. - -
- - HAVE_SYSCALL_TRACEPOINTS ------------------------ --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -71,7 +71,6 @@ config SUPERH32 select HAVE_FUNCTION_TRACER select HAVE_FTRACE_MCOUNT_RECORD select HAVE_DYNAMIC_FTRACE - select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE select ARCH_WANT_IPC_PARSE_VERSION select HAVE_FUNCTION_GRAPH_TRACER select HAVE_ARCH_KGDB --- a/arch/sh/kernel/traps.c +++ b/arch/sh/kernel/traps.c @@ -170,11 +170,21 @@ BUILD_TRAP_HANDLER(bug) force_sig(SIGTRAP); } +#ifdef CONFIG_HAVE_DYNAMIC_FTRACE +extern void arch_ftrace_nmi_enter(void); +extern void arch_ftrace_nmi_exit(void); +#else +static inline void arch_ftrace_nmi_enter(void) { } +static inline void arch_ftrace_nmi_exit(void) { } +#endif + BUILD_TRAP_HANDLER(nmi) { unsigned int cpu = smp_processor_id(); TRAP_HANDLER_DECL; + arch_ftrace_nmi_enter(); + nmi_enter(); nmi_count(cpu)++; @@ -190,4 +200,6 @@ BUILD_TRAP_HANDLER(nmi) } nmi_exit(); + + arch_ftrace_nmi_exit(); } --- a/include/linux/ftrace_irq.h +++ b/include/linux/ftrace_irq.h @@ -2,15 +2,6 @@ #ifndef _LINUX_FTRACE_IRQ_H #define _LINUX_FTRACE_IRQ_H - -#ifdef CONFIG_FTRACE_NMI_ENTER -extern void arch_ftrace_nmi_enter(void); -extern void arch_ftrace_nmi_exit(void); -#else -static inline void arch_ftrace_nmi_enter(void) { } -static inline void arch_ftrace_nmi_exit(void) { } -#endif - #ifdef CONFIG_HWLAT_TRACER extern bool trace_hwlat_callback_enabled; extern void trace_hwlat_callback(bool enter); @@ -22,12 +13,10 @@ static inline void ftrace_nmi_enter(void if (trace_hwlat_callback_enabled) trace_hwlat_callback(true); #endif - arch_ftrace_nmi_enter(); } static inline void ftrace_nmi_exit(void) { - arch_ftrace_nmi_exit(); #ifdef CONFIG_HWLAT_TRACER if (trace_hwlat_callback_enabled) trace_hwlat_callback(false); --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -10,11 +10,6 @@ config USER_STACKTRACE_SUPPORT config NOP_TRACER bool -config HAVE_FTRACE_NMI_ENTER - bool - help - See Documentation/trace/ftrace-design.rst - config HAVE_FUNCTION_TRACER bool help @@ -72,11 +67,6 @@ config RING_BUFFER select TRACE_CLOCK select IRQ_WORK -config FTRACE_NMI_ENTER - bool - depends on HAVE_FTRACE_NMI_ENTER - default y - config EVENT_TRACING select CONTEXT_SWITCH_TRACER select GLOB